PITTSBURGH -- Bishops, nuns and rabbis are joining the environmental and social debate over natural gas drilling in the Marcellus Shale region, and many are seeking a balance that reflects their congregations.

"We have people's lives who are being blessed or adversely affected by this," said Bishop Thomas Bickerton of Pittsburgh, who leads more than 800 United Methodist congregations and 187,000 members in western Pennsylvania, where major drilling is taking place.

"The conversations within the church are rather lively and robust," Bickerton said, and he thinks gas drilling "warrants some careful looking" by religious groups and public officials.

Bickerton told The Associated Press that it's a delicate topic. On one hand, he's very supportive of the economic development which gas drilling has spurred across the region. On the other, he said it appears the state has not thoroughly looked at all the issues around drilling, its impact on communities and the environment.

And as a West Virginia native, he's seen how mining for another natural resource – coal – has helped and hurt communities.

Energy companies have identified major reserves of natural gas throughout the Marcellus Shale, a shale formation that underlies much of New York and Pennsylvania, and parts of Maryland, Ohio and West Virginia.

More than 3,300 wells have been drilled across Pennsylvania in just the last few years. The boom has raised concerns about the use of hydraulic fracturing, or fracking, which injects chemical-laced water to break up the shale and allow natural gas to escape into the shale to push out the minerals. Environmental groups and the Environmental Protection Agency have expressed concerns about how the process impacts water, soil and air quality. But the industry insists it is safe.

Bickerton is one of several religious and community leaders who last month signed a protest letter to U.S. Secretary of Energy Steven Chu. The letter, which originated with the Environmental Working Group of Washington, D.C., questioned the makeup of a federal committee that is reviewing fracking impacts, and asked for more community involvement in the review process.

Bickerton's western Pennsylvania United Methodist Conference is one of many groups that have used church publications to examine the benefits and pitfalls of fracking. An article titled "The Morality of Fracking" appeared in The National Catholic Reporter last month, and the Reform Jewish Voice of New York State endorsed the drilling moratorium there.

Scientific and environmental issues aren't the only concern.

"I believe personally that the church does have responsibility to engage the wider body of the community about what's moral and what's not. What's ethical and what's not," said Bickerton. He said he doesn't want to inhibit economic growth, yet is concerned that some in his congregation have been taken advantage of, such as with contracts they don't understand or side effects they haven't considered.

Norman Wirzba, a professor of Theology, Ecology, and Rural Life at Duke Divinity School in North Carolina, said he thinks it's noteworthy that Bickerton, the leader of a large congregation, is speaking out.

"There is a history within American Christianity with just being concerned with getting the soul to heaven," Wirzba said. Religious environmental activism dates back to the 1950s and 60s, but it often presents great challenges at the local level. If a religious group seeks to change the whole economic system, then the very livelihood of the people they serve can be put into jeopardy, he said.

"What you really need is a kind of activism that can speak out against injustices, but also propose alternatives," Wirzba said. "The last thing we need is well-meaning environmentalists running around the world telling people how to live."

Fracking is one of many environmental issues that religious groups have debated in recent years. The National Religious Partnership for the Environment includes perspectives from Evangelical, Catholic, Protestant, Jewish and Interfaith groups. In April, the Kentucky group Blessed Earth used the slogan "Make Earth Day a Church Day" and a "Green Bible" was recently published, with essays and "passages that speak to God's care for creation highlighted in green."

In some cases, religious groups see gas drilling as a way to support charitable work.

Kathryn Klaber, president of the Marcellus Shale Coalition, a drilling industry group, said she was surprised last year to find that dozens of religious groups had entered into gas drilling leases.

"That to me was real eye-opener, when you're literally funding mission through the leasing of mineral rights," said Klaber, who believes religious groups can help in the process of distributing some of the newfound wealth that gas drilling is generating.

One example is Camp Agape, a bible camp set on 257 acres in Hickory, Pa., about 25 miles southwest of Pittsburgh. It was founded 50 years ago, and is owned and operated by an association made up of 17 congregations from the Evangelical Lutheran Church of America.

About four years ago the camp decided to lease drilling rights to Range Resources, said Charles Wingert, a member of the all-volunteer board of directors.

"It's been a good experience for us. Not without some worry and trepidation," Wingert said. "Basically we were living on a shoestring for many, many years."

The camp, which serves about 150 children each summer, runs a program that provides intensive tutoring for kids who are struggling with reading and math.

"We're really enthused that we're able to help children, and we couldn't do this without the additional income," Wingert said. The lease payments have also helped in upgrading the camp and keeping fees low, and may ultimately provide for an endowment. They've also helped the camp survive.

"I think we would not be here without the income," said Wingert, who added that board members felt that the gas below the camp is part of God's creation, just like forests and streams.

Some religious groups think another way to address the fracking issue is to start at the top, by engaging and pressuring large corporations.

Sister Nora Nash is director of the corporate social responsibility program at the Sisters of St. Francis of Philadelphia, which was founded more than 150 years ago. The order began caring for smallpox patients in 1858 and opened St. Mary's Hospital for the poor in 1860.

The group has a long history of asking the corporations in which the sisters invest to be more socially conscious. Nash visited western Pa. last year to talk to people in communities where fracking was taking place, and was disturbed by what she saw. Her group also signed the protest letter to the Secretary of Energy.

"All of the poorest of the poor are not getting the jobs. Everyplace we looked there was a white truck from Oklahoma or Texas," she said.

Earlier this year the Sisters of St. Francis joined with other religious groups to file a formal shareholder proposal with energy giant Chevron, which has purchased large holdings in the Marcellus region.

The proposal asked Chevron to look at ways to go "above and beyond regulatory requirements" and reduce or eliminate hazards to air, water and soil quality from fracking. Several related proposals were put before energy companies, and Nash was encouraged by the response. On average, the shareholder proposals seeking greater transparency on fracking got 30 percent of the vote, and in one case, 42 percent.

Chevron's board responded to the shareholder fracking proposal by noting that the company "is already committed to meeting or exceeding all applicable laws and regulations," and that the new suggestions "would merely duplicate Chevron's current efforts and thus would be a waste of stockholder money."

But over time it is possible to influence corporations, Nash said.

"We are active in shareholder advocacy. We've been working with Chevron for about 10 years. And last year Chevron did sign a human rights policy. And we felt really good about that," Nash said.

"I think their intentions are good," Nash said of Chevron. "But they have a long way to go to look at the significant risks to human health" that fracking may pose.

Wirzba said the North Carolina Council of Churches is working on a statement, and Rabbi Arthur Waskow of Philadelphia's Shalom Center has written articles critical of fracking.

Sybil Sanchez, director of the New York-based Coalition on Environment and Jewish Life, said her group supports increasing energy independence in ways that also protect the environment, which they see as God's Creation. But fracking is of particular concern because of the number of unknown chemicals used and the impact it has on local citizens and their access to clean water, Sanchez said.

Ultimately, Wirzba said that if religious groups want to change how natural gas drilling interacts with communities, words aren't enough.

"You're not going to change the lives of people really, unless you live with them," he said. "That means you can't do it just by holding a poster. You gotta do it by moving into a neighborhood."